High data reliability, high speed of memory access, lower power consumption and reduced scaling of chip size are features that are demanded from semiconductor memory. The reduced scaling of the chip size typically results in smaller feature sizes and lower power consumption for the various circuits of semiconductor memory. For example, a memory array, supporting circuits for receiving signals and providing signals, and other circuits used in performing various memory operations may be designed for higher memory and circuit density and reduced power consumption. Lower power consumption is often achieved by using lower internal voltages. However, circuit performance when operating at higher speeds may suffer when lower internal voltages are used. Additionally, operation of circuits at higher speeds (e.g., higher clock frequencies) typically have higher power consumption compared to operating at lower speeds. Thus, circuits are often designed to balance lower power consumption and acceptable performance at higher speeds. It may be desirable to have circuits for semiconductor memories that may be configured to be operated for lower power consumption or for high speed performance.